/// <summary>
/// Renders the specified scene.
/// </summary>
/// <param name="scene">The scene.</param>
/// <param name="camera">The camera.</param>
/// <returns>
/// The scene rendered with raytracing.
/// </returns>
public Image Render(Scene scene, Camera camera)
{
// Useful references.
OpenGL gl = scene.OpenGL;
// First, we need the matricies and viewport.
double[] modelview = new double[16];
double[] projection = new double[16];
int[] viewport = new int[4];
gl.GetDouble(OpenGL.GL_MODELVIEW_MATRIX, modelview);
gl.GetDouble(OpenGL.GL_PROJECTION_MATRIX, projection);
gl.GetInteger(OpenGL.GL_VIEWPORT, viewport);
int screenwidth = viewport[2];
int screenheight = viewport[3];
// From frustum data, we make a screen origin, and s/t vectors.
Vertex s = new Vertex(0, 0.03f, 0);
Vertex t = new Vertex(0, 0, 0.05f);
Vertex vScreenOrigin = new Vertex(0, 0, 5);
// Go through every pixel we have, and convert it into a screen pixel.
ScreenPixel[] pixels = new ScreenPixel[viewport[2] * viewport[3]];
for (int y = 0; y < screenheight; y++)
{
for (int x = 0; x < screenwidth; x++)
{
// Get plane coordinates first of all.
int planeX = x - (screenwidth / 2);
int planeY = y - (screenwidth / 2);
float worldX = vScreenOrigin.X + (planeX * t.X) + (planeY * s.X);
float worldY = vScreenOrigin.Y + (planeX * t.Y) + (planeY * s.Y);
float worldZ = vScreenOrigin.Z + (planeX * t.Z) + (planeY * s.Z);
// Finally, pack all that data into a ScreenPixel.
ScreenPixel pixel = new ScreenPixel();
pixel.x = x;
pixel.y = y;
pixel.worldpos = new Vertex(worldX, worldY, worldZ);
pixel.ray.origin = camera.Position;
pixel.ray.direction = pixel.worldpos - camera.Position;
pixels[(y * viewport[2]) + x] = pixel;
}
}
// Create the resulting bitmap.
System.Drawing.Bitmap bmp = new System.Drawing.Bitmap(viewport[2], viewport[3]);
// Now go through every ray and test for intersections.
int pixelcounter = 0;
int pixelcount = viewport[2] * viewport[3];
foreach (ScreenPixel pix in pixels)
{
// Raytrace the polygons.
Intersection closest = new Intersection();
foreach (var raytracable in scene.SceneContainer.Traverse(se => se is IRayTracable))
{
Intersection i = ((IRayTracable)raytracable).Raytrace(pix.ray, scene);
if (i.intersected && (closest.intersected == false || i.closeness < closest.closeness))
closest = i;
}
if (closest.intersected == true)
{
System.Console.WriteLine("i = {0}, only {1} left!\n",
closest.closeness, pixelcount - pixelcounter);
}
bmp.SetPixel(pix.x, pix.y, pix.ray.light);
pixelcounter++;
}
// Return the ray traced imag.
return bmp;
}